to go in, to enter: to pass inside a place, or into the presence of someone in authority.
This is the everyday Aramaic verb for going inside. Someone crosses a threshold and is now within: the queen walks into the hall where the feast is going on, and Daniel goes into his own house to pray at the open window.
Most of the time in Daniel, though, what is entered is not a building but a person's presence. The book is set in a royal court, where getting in front of the king happens at an appointed moment, and this is the word for that moment. Daniel goes in to ask for more time, the palace experts file in and stand before the throne, and Daniel comes in last of all when nobody else can read the writing. The formality belongs to the setting, not to the word. On its own it says only that someone went in.
Aramaic has other verbs for closing a distance, and they do not overlap with this one: